Multi-Tissue Transcriptomics for Systematic Identification and Expression Analysis of Detoxification Genes in Calliptamus barbarus

Calliptamus barbarus is a dominant pest of desert and semi-desert grasslands in Xinjiang, China, yet its detoxification metabolism gene repertoire and its tissue-level organization remain poorly characterized. Here, we sequenced the transcriptomes of four key detoxification tissues (gastric caeca, midgut, Malpighian tubules and fat body; three biological replicates each) and, using BLAST- and HMMER-based searches against reference proteins from Drosophila melanogaster and Locusta migratoria, identified 1602 detoxification metabolism genes in five families (COE 522, P450 470, UGT 276, ABC 233 and GST 101). Phylogenetic comparison with Locusta migratoria and Schistocerca gregaria showed that the xenobiotic-metabolism subfamilies (CYP3, CYP4, α-esterase, Sigma-GST, UGT305 and ABCB/ABCC) are compositionally overrepresented and species-specifically clustered in C. barbarus, whereas subfamilies serving basic physiological roles are conserved. Among 188 tissue-expressed genes, expression was functionally partitioned across tissues: the gastric caeca dominated Phase II conjugation (GST, UGT) and hydrolysis (COE), whereas the Malpighian tubules dominated Phase I oxidation (P450) and Phase III efflux (ABC). RT-qPCR of 11 tissue-biased genes spanning all five families reproduced the transcriptome direction in 11 of 11 cases (two-sided sign test p = 0.001) and agreed quantitatively with the FPKM fold changes (Pearson r = 0.98), confirming the strongest tissue biases for Ugt49B1 and MRP-PO (gastric caeca and midgut, more than 25-fold). These findings provide a detoxification genes resource and a tissue-level functional map for understanding xenobiotic metabolism and environmental adaptation in C. barbarus.